I had a FPSS fail completly. Doesn't hurt anything. It had been in use for about four years. Just because it failed will I stop using them, no way, I allready replaced it for safety. Like any Mechanicl/electrical device there is a failure rate in the field after a long hard use.
Robert

 

I had to reply after 40 views Rob. Oh well, you knwo how to put a new one in so your covered. Helps when your smart doesn't it. I wish I coudl say the same

Gary

 

God I love charity posts.
Robert

 

Well, luckily it wasnt !FPSS and lost fuel pressure. Guess I will have to get me one of these now.

 

Robert,

How did you discover that it had failed? Did it fail in such a way that the system was inoperable while it was in place? Thanks!

 

I'm hoping that when I drop my wet kit in, my FPSS cooperates...

 

Yeah, How did you know it Failed?

 

I've seen my fair share fail as well. As you know I tested a few calibrated to an NIST standard and noticed a problem when subjected to vibration.

 

It was a total n2o shut down (like it should be). After breaking in my clutch, I was ready to try some n2o runs and noticed my Et and traps remained as an N/A run. So after a little diagnosotic work, realized the FPSS had failed (not out of wack setting wise). I believe I know why it failed. NOS on the 5177 kits has the fpss wired into the ground for the redundant noids. Other companys avoid doing this as the noid amp draw can be quite high, and fpss was designed for low amp use. With that said, the normal 5177 has low amp draw noids; however, I am running two kits (dual stage) with all grounds going through the fpss. This is probably a little more current than it was designed for. So in conclusion, user error was probably the biggest factor. I haven't yet rewired but plan on doing so, and using the gound out of my window sw instead.
Robert

 

By being in the power circuit that switch could have just as easily fused together, and the system would continue to spray nitrous, regardless of fuel pressure...Your right though, that one was on you.. They are not made with solid state electronics, which is another reason I prefer to avoid them....

On a similar note, I once wired an Msd window switch using an unswitched power source....wondered why the battery would drain down within three days...

 

I don't like them personally. Never had one work right for me. Got a lot of on off surging off the line and the a/f on my wideband was cool and pressure wasn't falling out on just a 100 shot. I canceled right out. If you are going to run one wire it on the ground in between the window switch and the relay trigger. Wiring them on multiple noid power grounds is too much power for them.